1. Field of the Invention
The present invention relates to laminates of a substrate and a polyether urethane foam and particularly to laminates that are produced by heat sealing. More particularly, the invention relates to urethane foam laminates wherein the urethane foam is treated with a phosphorus-containing additive and a polyalkylene glycol additive.
2. Description of the Prior Art
In U.S. Pat. No. 4,616,044, issued Oct. 7, 1986, a heat laminatable polyether urethane foam is described which contains an effective amount of an organophosphorus additive to impart heat laminatable properties on the resulting foam. The organophosphorus additives that are described in this patent include organophosphites derived from phosphorus acid, organophosphonates derived from phosphonic acid, and organophosphates derived from phosphoric acid.
U.S. Pat. No. 4,696,952 relates to the production of polyurethane foams having good skin weld ability. The foams that are described in this patent use a flame retardant which is a triaryl phosphate ester which is described as having the disadvantage of markedly impairing the weldability of the product. In order to improve the flame retardance and weldability of the resulting foam, a combination of a high molecular weight polyhydroxy compound and a low molecular weight polyhydroxy compound is proposed for use. The high molecular weight polyhydroxy compound is similar to the conventional materials that are used as the basis for polyurethane foams. The low molecular weight polyhydroxy compound which is present in much lower amount is indicated as being an aliphatic alcohol having a hydroxy number of greater than 560 with 2 to 4 hydroxy groups in the molecule. Examples of such compounds include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-propanediol, and triethylene glycol. Other examples include such triols as glycerol, trimethylolpropane, triethylolpropane, trimethylolethane, triethylolethane, pentaerythritol, and 1,2,6-hexanetriol.